#!/usr/bin/env python3
# -*- coding: utf-8 -*-
print('#############条件语句，根据岁数判断，if...elif...else...#############')
age = 20
if age >= 18:
    print("成年人")
    print("不用大括号")
elif age >= 12:
    print("年轻人")
    print('不用大括号')
else:
    print("小孩子")
    print('不用大括号')
print('#############条件语句，简化版#############')
print('输入体重：')
weight = input()
temp = int(weight)
if temp >= 18:
    print("成年人")
    print("不用大括号")
elif temp >= 12:
    print("年轻人")
    print('不用大括号')
else:
    print("小孩子")
    print('不用大括号')
